/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 31.05.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 * 
 * the unrar licence applies to all junrar source and binary distributions 
 * you are not allowed to use this source to re-create the RAR compression algorithm
 * 
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&#038;" or "&amp;"
 * "<":  "&#060;" or "&lt;"
 * ">":  "&#062;" or "&gt;"
 * "@":  "&#064;" 
 */
package com.github.junrar.unpack.vm;

/**
 * DOCUMENT ME
 * 
 * @author $LastChangedBy$
 * @version $LastChangedRevision$
 */
public class BitInput
 {
  /**
   * the max size of the input
   */
  public static final int MAX_SIZE = 0x8000;
  protected int inAddr;
  protected int inBit;
  protected byte[] inBuf;

  /**
	 * 
	 */
  public void InitBitInput()
   {
    inAddr = 0;
    inBit = 0;
   }

  /**
   * @param Bits
   */
  public void addbits(int Bits)
   {
    Bits += inBit;
    inAddr += Bits >> 3;
    inBit = Bits & 7;
   }

  /**
   * @return the bits (unsigned short)
   */
  public int getbits()
   {
    // int BitField=0;
    // BitField|=(int)(inBuf[inAddr] << 16)&0xFF0000;
    // BitField|=(int)(inBuf[inAddr+1] << 8)&0xff00;
    // BitField|=(int)(inBuf[inAddr+2])&0xFF;
    // BitField >>>= (8-inBit);
    // return (BitField & 0xffff);
    return (((((inBuf[inAddr] & 0xff) << 16) + ((inBuf[inAddr + 1] & 0xff) << 8) + ((inBuf[inAddr + 2] & 0xff))) >>> (8 - inBit)) & 0xffff);
   }

  /**
     *  
     */
  public BitInput()
   {
    inBuf = new byte[MAX_SIZE];
   }

  /**
   * @param Bits
   *         add the bits
   */
  public void faddbits(int Bits)
   {
    addbits(Bits);
   }

  /**
   * @return get the bits
   */
  public int fgetbits()
   {
    return (getbits());
   }

  /**
   * Indicates an Overfow
   * 
   * @param IncPtr
   *         how many bytes to inc
   * @return true if an Oververflow would occur
   */
  public boolean Overflow(int IncPtr)
   {
    return (inAddr + IncPtr >= MAX_SIZE);
   }

  public byte[] getInBuf()
   {
    return inBuf;
   }

 }
